Global impacts of fire regimes on wildland bird diversity

Fire is a natural disturbance that significantly impacts ecosystems and plays a crucial role in the distribution and preservation of biota worldwide. The effects of fires on bird diversity can be both positive, as they can create new habitats, and negative, as they can reduce nesting success. To fully understand the ecological implications of wildfires, we need to understand the spatial distribution of wildland bird diversity and fire regimes and how fire regimes affect wildland bird diversity ecosystems. Using data collected at a global scale, we examined effects of time-averaged fire regimes on the spatial diversity of wildland bird species. Initially, we used the MaxEnt algorithm to model the potential distribution of 1,115 wildland bird species over a 20-year period. We also processed satellite observations of burned areas (FIRECCI51) during the same period to estimate fire regime characteristics, including the average proportion of burnt vegetation, interannual variability in the burnt area, and fire intensity. Finally, the association between wild bird diversity and fire variables in each biome was determined through Spearman, Bonferroni, and Kruskal-Wallis statistics. Our findings revealed that (I) the most affected wildland bird communities are those found in tropical ecosystems, where the majority of fires occur; (II) high fire intensity values and a substantial proportion of burned vegetation have a positive impact on maintaining a diverse population of wildland birds in biomes characterized by savannah or grassland covers, as seen in temperate or tropical zones. Conversely, low fire intensity values and a smaller proportion of burned vegetation also promote greater diversity of wildland birds in boreal or temperate zones, and (III) in Mediterranean ecosystems, a clear association between wildland bird diversity and wildfires could not be established. This research could help identify areas that are ecologically vulnerable to wildfires. It could also be useful in guiding regional studies aligned with developing sustainable landscape management practices and conserving priority ecological zones in tropical ecosystems.